Evidence for the singly Cabibbo-suppressed decay {Omega}_c^0to {Xi}^{-}{pi}^{+} and search for {Omega}_c^0to {Xi}^{-}{K}^{+} and Ω−K+ decays at Belle

Abstract

Using a data sample of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider, we study for the first time the singly Cabibbo-suppressed decays {Omega}_c^0to {Xi}^{-}{pi}^{+} and Ω−K+ and the doubly Cabibbo-suppressed decay {Omega}_c^0to {Xi}^{-}{K}^{+} . Evidence for an {Omega}_c^0 signal in the {Omega}_c^0 → Ξ−π+ mode is reported with a significance of 4.5σ including systematic uncertainties. The ratio of branching fractions to the normalization mode {Omega}_c^0 → Ω−π+ is measured to beBΩc0→Ξ−π+/BΩc0→Ω−π+=0.253±0.052stat.±0.030syst..\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{B}\\left({\\Omega}_c^0\ o {\\Xi}^{-}{\\pi}^{+}\\right)/\\mathcal{B}\\left({\\Omega}_c^0\ o {\\Omega}^{-}{\\pi}^{+}\\right)=0.253\\pm 0.052\\left(\ extrm{stat}.\\right)\\pm 0.030\\left(\ extrm{syst}.\\right). $$\\end{document}No significant signals of {Omega}_c^0to {Xi}^{-}{K}^{+} and Ω−K+ modes are found. The upper limits at 90% confidence level on ratios of branching fractions are determined to beBΩc0→Ξ−K+/BΩc0→Ω−π+<0.070\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{B}\\left({\\Omega}_c^0\ o {\\Xi}^{-}{K}^{+}\\right)/\\mathcal{B}\\left({\\Omega}_c^0\ o {\\Omega}^{-}{\\pi}^{+}\\right)<0.070 $$\\end{document}andBΩc0→Ω−K+/BΩc0→Ω−π+<0.29.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{B}\\left({\\Omega}_c^0\ o {\\Omega}^{-}{K}^{+}\\right)/\\mathcal{B}\\left({\\Omega}_c^0\ o {\\Omega}^{-}{\\pi}^{+}\\right)<0.29. $$\\end{document}